Metformin Hydrocloride tablets prescribed for treatment of non-insulin dependent diabetes mellitus (NIDDM). The aim of the study is to compare the differences in dissolution behavior and asses bioequivalence of some commercially available Metformin Hydrocloride tablets in Vijayawada. The objective is to find out potent generic brand and reduce the cost of treatment for diabetes mellitus with respect to its composition and manufacturer. Eight generic brands manufactured by different companies were evaluated for physicochemical properties, drug content, in vitro dissolution studies and compared with each other. The in vitro dissolution studies were performed in USP Dissolution Apparatus II using pH 6.8 phosphate buffer solution for 1 hr. The bioequivalence was assessed based on In vitro dissolution profile and f1 & f2 factors. In vitro dissolution of all the brands was satisfactory and the brand Obimet® shown highest dissolution of 94.49% within 1 hr. The f1 and f2 values were in the range of 2 – 8 and 74 – 93 respectively. It is evident that test products were bioequivalent to the reference product and the brand Obimet® could be used as a best generic substitute which reduce the dose and cost of treatment for diabetes mellitus.